With a presidential campaign, health care and the gun control debate in the news these days, one can't help getting sucked into the flame wars that are Internet comment threads. But psychologists say this addictive form of vitriolic back and forth should be avoided — or simply censored by online media outlets — because it actually damages society and mental health.

These days, online comments "are extraordinarily aggressive, without resolving anything," said Art Markman, a professor of psychology at the University of Texas at Austin. "At the end of it you can't possibly feel like anybody heard you. Having a strong emotional experience that doesn't resolve itself in any healthy way can't be a good thing."

If it's so unsatisfying and unhealthy, why do we do it?

A perfect storm of factors come together to engender the rudeness and aggression seen in the comments' sections of Web pages, Markman said. First, commenters are often virtually anonymous, and thus, unaccountable for their rudeness. Second, they are at a distance from the target of their anger — be it the article they're commenting on or another comment on that article — and people tend to antagonize distant abstractions more easily than living, breathing interlocutors. Third, it's easier to be nasty in writing than in speech, hence the now somewhat outmoded practice of leaving angry notes (back when people used paper), Markman said. [Infographic: A Typical Day on the Internet]

And because comment-section discourses don't happen in real time, commenters can write lengthy monologues, which tend to entrench them in their extreme viewpoint. "When you're having a conversation in person, who actually gets to deliver a monologue except people in the movies? Even if you get angry, people are talking back and forth and so eventually you have to calm down and listen so you can have a conversation," Markman told Life's Little Mysteries.